JEE Main 2023ChemistrySurface ChemistryMediumMCQ

JEE Main 2023Surface Chemistry Question with Solution

JEE Main 2023 (29 Jan Shift 1)

Question

Which of the following salt solutions would coagulate the colloid soloution formed when FeCl3 is added to NaOH solution, at the fastest rate?

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Show full solutionCorrect option: A
Correct answer
A10 mL of 0.2 mol dm-3 AlCl3

Step-by-step explanation

Generally, the greater the valence of the flocculating ion added, the greater its power to cause precipitation. In the coagulation of a negative sol, the flocculating power is in the order: 

Al3+ > Ba2+ > Na+

FeCl3 with NaOH forms a negative sol.

So, AlCl3 coagulate it most.

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About this question

This is a previous-year question from JEE Main 2023, covering the Surface Chemistry chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.